Sheet guide device and sheet guiding method

ABSTRACT

A sheet guide device according to an embodiment includes: a sheet carrying unit which carries a sheet from a paper discharge port of an image forming apparatus to a paper supply port of a finishing apparatus; and a pair of guide plates having one end attached to an inner side of the paper discharge port so as to be narrowed in a tapered form from the paper discharge port toward the paper supply port and having the other end attached to an inner side of the paper supply port. The pair of guide plates has one of the one end and the other end as a fulcrum and has the other as a turning end. When the paper discharge port and the paper supply port are shifted from each other in height position, the turning end turns according to the quantity of shift in the height position.

CROSS-REFERENCE TO RELATED APPLICATION

This application is based upon and claims the priority of U.S. Provisional Application No. 61/311,240, filed on Mar. 5, 2010, and U.S. Provisional Application No. 61/311,239, filed on Mar. 5, 2010, the entire contents of which are incorporated herein by reference.

FIELD

Embodiments described herein relate generally to a sheet guide device and a sheet guiding method for guiding a sheet from an image forming apparatus to a sheet finishing apparatus.

BACKGROUND

Recently, an image forming apparatus (for example, MFP) is provided with a finishing apparatus subsequently to and in the immediate vicinity to the MFP in order to finish a sheet after image formation. The finishing apparatus is called a finisher. The finisher staples sheets that are sent out from the MFP or punches holes in the sheets, and discharges the sheets to a storage tray from a paper discharge port.

When the finishing apparatus is attached subsequently to the image forming apparatus, the height of the discharge port of the image forming apparatus and the height of a paper supply port of the finishing apparatus are designed to be the same. However, when the floor surface where the image forming apparatus and the finishing apparatus are installed is not flat, it takes time to adjust the heights of the paper discharge port and the paper supply port.

When the height of the paper discharge port and the height of the paper supply port are different, generating a step, delivery of sheets from the image forming apparatus to the finishing apparatus fails and jam may occur. Moreover, when the MFP body is installed in a place like on a carpet, even if the heights are adjusted, the MFP body with a heavy weight may sink and height may shift.

Generally, in the case of delivering a sheet between two apparatuses, the guide in the downstream apparatus is tapered to guide the sheet. However, the difference in sheet carrying height between the upstream apparatus and downstream apparatus can only be allowed within a narrow range. A wider taper angle of the guide is preferable in order to expand the allowable range. However, the wider taper angle causes increase in the angle at which the forward edge of the sheet contact the guide. Therefore, the forward edge of the sheet ends up bending. Also, to expand the allowable range without widening the taper angle of the guide, the length of the guide must be extended, causing the downstream apparatus to increase in size.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a configuration view showing an image forming apparatus and a finishing apparatus according to one embodiment in a separate state.

FIG. 2 is a front view showing a guide mechanism used in a sheet guide device according to the one embodiment.

FIG. 3 is a plan view showing a guide plate of the guide mechanism in the one embodiment.

FIG. 4 is an exploded perspective view of the guide mechanism in the one embodiment.

FIG. 5 is an explanatory view showing the operation of the guide mechanism in the one embodiment.

FIG. 6 is another explanatory view showing the operation of the guide mechanism in the one embodiment.

FIG. 7 is a front view showing a modification of the guide mechanism in the one embodiment.

FIG. 8 is an explanatory view showing the operation of the guide mechanism shown in FIG. 7.

FIG. 9 is a front view showing an image forming apparatus and a finishing apparatus in a separate state in order to explain a sheet guide device according to a second embodiment.

FIG. 10 is a front view showing a guide mechanism used in the sheet guide device according to the second embodiment.

FIG. 11 is a side view showing the guide mechanism in the second embodiment.

FIG. 12 is an exploded perspective view of the guide mechanism in the second embodiment.

FIG. 13 is an explanatory view showing the operation of the guide mechanism in the second embodiment.

FIG. 14 is another explanatory view showing the operation of the guide mechanism in the second embodiment.

FIG. 15 is a front view showing a modification of the guide mechanism in the second embodiment.

FIG. 16 is an explanatory view showing the operation of the guide mechanism shown in FIG. 15.

DETAILED DESCRIPTION

A sheet guide device according to an embodiment includes:

a sheet carrying unit which carries a sheet from a paper discharge port of an image forming apparatus to a paper supply port of a finishing apparatus; and

a pair of guide plates having one end attached to an inner side of the paper discharge port so as to be narrowed in a tapered form from the paper discharge port toward the paper supply port and having the other end attached to an inner side of the paper supply port, the pair of guide plates has one of the one end and the other end as a fulcrum and has the other as a turning end, and when the paper discharge port and the paper supply port are shifted from each other in height position, the turning end turns according to the quantity of shift in the height position.

Hereinafter, a sheet guide device according to an embodiment will be described in detail with reference to the drawings. In the drawings, the same parts are denoted by the same reference numerals.

In FIG. 1, an image forming apparatus 10 is, for example, an MFP (multi-function peripheral), printer, copy machine or the like. A finishing apparatus 20 is arranged in the immediate vicinity to the image forming apparatus 10.

The finishing apparatus 20 has, for example, a stapler (finishing unit) which staples plural sheets supplied from the image forming apparatus 10. The finishing apparatus 20 is hereinafter called the finisher 20. FIG. 1 shows a state where the MFP 10 and the finisher 20 are separated.

A document table is provided on top of a body 11 of the MFP 10. An automatic document feeder (ADF) 12 is provided on the document table in a way that the ADF 12 can freely open and close. An operation panel 13 is also provided on top of the body 11. The operation panel 13 has an operation unit 14 including various keys, and a touch panel-type display unit 15.

A scanner unit 16 is provided below the ADF 12 in the body 11. The scanner unit 16 reads a document sent by the ADF 12 or a document placed on the document table and generates image data. A printer unit 17 is provided at a central part in the body 11. Plural cassettes 18 housing sheets of various sizes are provided in a lower part of the body 11.

The printer unit 17 includes a photoconductive drum and a laser or the like. The printer unit 17 processes image data read by the scanner unit 16 or image data produced on a PC (personal computer) or the like and forms an image on a sheet. The printer unit 17 scans the surface of the photoconductive drum with a laser beam from the laser and thus exposes the surface of the photoconductive drum to light, producing an electrostatic latent image on the photoconductive drum. A charger, a developing device, a transfer device and the like are arranged around the photoconductive drum. The electrostatic latent image on the photoconductive drum is developed by the developing device and a toner image is thus formed on the photoconductive drum. The toner image is transferred to a sheet by the transfer device. As the configuration of the printer unit 17, there are various other systems than the above example.

The sheet on which the image is formed by the printer unit 17 passes through a first carrying path 41 and is discharged to a paper discharge tray 43. Alternatively, the sheet passes through a second carrying path 42 and is discharged to the finisher 20 by paper discharge rollers 19. The first carrying path 41 and the second carrying path 42 are provided in parallel in the direction of height and form a sheet carrying path through which to carry a sheet on which an image is formed by the printer unit 17. When finishing of a sheet S is not carried out, the sheet is carried to the paper discharge tray 43 through the carrying path 41. When finishing of the sheet S is carried out, the sheet is carried to the finisher 20 through the carrying path 42.

The finisher 20 is to staple sheets and has a standby tray 21, a processing tray 22 and a stapler 23. The sheet S is received by entrance rollers 24 provided at an in carrying-in port of the finisher 20. The entrance rollers 24 include an upper roller and a lower roller and are driven by a motor.

Paper supply rollers 25 are provided downstream of the entrance rollers 24. The sheet S received by the entrance rollers 24 is sent to the standby tray 21 via the paper supply rollers 25. Below the standby tray 21, the processing tray 22 is arranged on which to stack the sheet S falling from the standby tray 21.

The standby tray 21 is structured to stack the sheet S thereon and to be able to open. When a predetermined number of sheets S are accumulated, the standby tray 21 opens and the sheets S fall onto the processing tray 22 by their own weight or by the activation of a fall assisting member which forces the sheets S to fall. The processing tray 22 supports the sheets S while the stapler 23 staples the sheets S.

The sheets fallen onto the processing tray 22 are guided to the stapler 23 by a roller 26. The sheets S are stapled by the stapler 23. The roller 26 is driven by a motor. The roller 26 rotates in the opposite directions when the roller 26 guides the sheets S toward the stapler 23 and when the roller 26 discharges the stapled sheets S.

At the time of stapling, the plural sheets S fallen from the standby tray 21 to the processing tray 22 are aligned in a longitudinal direction that is the carrying direction and also aligned in a lateral direction orthogonal to the carrying direction, and are then stapled. A lateral alignment board 27 is provided in order to align the sheets S in the lateral direction. The lateral alignment board 27 carries out the lateral alignment and sorting of the sheets S.

To assist the sheets S in falling onto the processing tray 22, a rotatable paddle 28 is provided at a position where the rear edge of the sheets S falls. The paddle 28 is attached to a rotation axis. The paddle 28 strikes the sheets S falling from the standby tray 21 down onto the processing tray 22 and thus sends the sheets S toward the stapler 23.

A stopper 29 which regulates the rear edge position of the sheets S is provided at an end of the processing tray 22 on the side of the stapler 23. Moreover, a carrying belt 30 is provided in order to carry the sorted or stapled sheets S to a storage tray 44. The carrying belt 30 is laid between pulleys 31 and 32 and is provided with a pawl member 30 a which hooks the rear edge of the sheets S to send the sheets S. The description of a mechanism to rotate the pulleys 31 and 32 is omitted.

As the carrying belt 30 turns in the direction of arrow t, the sheets S are discharged from a discharge port 33 to the storage tray 44. The storage tray 44 is moved up and down by a motor and receives the sheets S. The carrying belt 30 and the pawl member 30 a guide the stapled sheets S to the discharge port 33. The sheets S that need not be stapled can be discharged to a fixed tray 45. A carrying path is provided in order to guide the sheets S to the fixed tray 45.

A foot 46 and a castor 47 are attached to the bottom side of the MFP 10. Castors 48 and 49 are attached to the bottom side of the finisher 20.

By the way, when both the MFP 10 and the finisher 20 are stand-alone apparatuses, if the floor surface where these apparatuses are installed has a concave and convex shape or if there are variances of the two apparatuses, the MFP 10 and the finisher 20 cannot be connected with each other successfully and the sheets cannot be carried successfully. Therefore, jam may occur.

In the embodiment, even when the floor surface where the MFP 10 and the finisher 20 are installed has a concave and convex shape or has a step, the difference in the installation height can be absorbed by a guide mechanism 50.

The guide mechanism 50 smoothly delivers the sheets S from the paper discharge rollers 19 of the MFP 10 to the entrance rollers 24 of the finisher 20. The guide mechanism 50 is provided at the connecting part between the MFP 10 and the finisher 20.

FIG. 2 is a front view showing the guide mechanism 50 as enlarged. FIG. 3 is a plan view showing a guide plate 62 (63) forming the guide mechanism 50. FIG. 4 is a perspective view showing the guide mechanism 50 as exploded. The sheet S is carried in the direction of arrow A.

The MFP 10 has a paper discharge port 51 formed on the side of the finisher 20. The finisher 20 has a paper supply port 61 facing the paper discharge port 51. The paper discharge rollers 19 are located on the inner side of the paper discharge port 51. The entrance rollers 24 are located on the inner side of the paper supply port 61.

The paper discharge rollers 19 form a sheet carrying unit which carries the sheet from the paper discharge port 51 of the MFP 10 to the paper supply port 61 of the finisher 20.

As shown in FIG. 4, hollows 52 and 53 are provided at both ends in the longitudinal direction of the paper discharge port 51. The hollow 52 is located to the upper side from the paper discharge rollers 19. The hollow 53 is located to the lower side from the paper discharge rollers 19. The hollows 52 and 53 are sloped toward their back.

On the inner side of the paper supply port 61, a pair of guide plates 62 and 63 is arranged from the paper supply port 61 toward the paper discharge port 51. As shown in FIG. 3 and FIG. 4, the guide plate 62 has an axis 64 at both ends on the side of the paper discharge port 51 and has an axis 66 at both ends on the side of the paper supply port 61. The axis 64 enters the hollow 52 and the axis 66 is inserted in holes 68 formed in supporting parts 70 on the inner side of the paper supply port 61. Therefore, the guide plate 62 can turn about the axis 66 as the fulcrum and the other end having the axis 64 serves as a turning end.

The guide plate 63 has the same configuration as the guide plate 62. The guide plate 63 has an axis 65 at both ends on the side of the paper discharge port 51 and has an axis 67 at both ends on the side of the paper supply port 61. The axis 65 enters the hollow 53 and the axis 67 is inserted in holes 69 formed in the supporting parts 70. The guide plate 63 can turn about the axis 67 as the fulcrum and the other end having the axis 65 serves as a turning end.

The axis 66 of the guide plate 62 is located more closely to the carrying path for the sheet S than the rotation axis of an upper roller 24A of the entrance rollers 24 is. The axis 67 of the guide plate 63 is located more closely to the carrying path for the sheet S than the rotation axis of a lower roller 24B is. Therefore, when the axes 64 and 65 of the guide plates 62 and 63 enter the hollows 52 and 53, the guide plates 62 and 63 form a tapered shape narrowing from the discharge port 51 toward the paper supply port 61 (see FIG. 2).

As shown in FIG. 3, plural concave parts 72 are provided on one edge of the guide plate 62 in order to prevent an upper roller 19A of the paper discharge rollers 19 from colliding, and plural concave parts 74 are provided on the other edge of the guide plate 62 in order to prevent the upper roller 24A of the entrance rollers 24 from colliding. Similarly, as shown in FIG. 4, plural concave parts 73 are provided on one edge of the guide plate 63 in order to prevent a lower roller 19B of the paper discharge rollers 19 from colliding, and plural concave parts 75 are provided on the other edge of the guide plate 63 in order to prevent the lower roller 24B of the entrance rollers 24 from colliding.

FIG. 2 shows the state where the guide mechanism 50 of FIG. 4 is assembled and the MFP 10 and the finisher 20 are connected with each other. The sheet S discharged by the paper discharge rollers 19 is guided by the guide plates 62 and 63 and carried to the entrance rollers 24.

FIG. 5 and FIG. 6 are explanatory views showing the operation of the guide mechanism 50 in the case where the MFP 10 and the finisher 20 are shifted in height. For example, when the floor surface where the finisher 20 is installed is higher than the floor surface where the MFP 10 is installed, the guide mechanism 50 operates as shown in FIG. 5.

In the state shown in FIG. 5, the axis 64 of the guide plate 62 goes deep into the hollow 52. The axis 65 of the guide plate 63 is located near the entrance of the hollow 53. The guide plates 62 and 63 turn slightly downward (clockwise) about the axes 66 and 67 as the fulcrum. The sheet S carried by the paper discharge rollers 19 is guided by the lower guide plate 63 and carried to the entrance rollers 24. Therefore, even when the height of the finisher 20 is higher, the sheet S is smoothly carried from the MFP 10 to the finisher 20.

Meanwhile, when the floor surface where the finisher 20 is installed is lower than the floor surface where the MFP 10 is installed, the guide mechanism 50 operates as shown in FIG. 6.

In the state shown in FIG. 6, the axis 64 of the guide plate 62 is located near the entrance of the hollow 52. The axis 65 of the guide plate 63 goes deep into the hollow 53. The guide plates 62 and 63 turn slightly upward (counterclockwise) about the axes 66 and 67 as the fulcrum. The sheet S carried by the paper discharge rollers 19 is guided by the upper guide plate 62 and carried to the entrance rollers 24. Therefore, even when the height of the finisher 20 is lower, the sheet S is smoothly carried from the MFP 10 to the finisher 20.

When the MFP 10 and the finisher 20 are not connected with each other, the ends of the guide plates 62 and 63 where the axes 64 and 65 are provided are hanging down because of their own weight. Therefore, when connecting the finisher 20 to the MFP 10, it is necessary to lift the axes 64 and 65 of the guide plates 62 and 63 and put the axes 64 and 65 in the hollows 52 and 53. Alternatively, when the axes 66 and 67 of the guide plates 62 and 63 are put and supported in the holes 68 and 69, the guide plates 62 and 63 may be energized by a torsion spring or the like so that the axes 64 and 65 of the guide plates 62 and 63 are directed toward the hollows 52 and 53.

The axis 66 of the guide plate 62 is located more closely to the carrying path for the sheet S than the rotation axis of the upper roller 24A is. The axis 67 of the guide plate 63 is located more closely to the carrying path for the sheet S than the rotation axis of the lower roller 24B is. Therefore, even when the height position of the finisher 20 changes slightly, the sheet S can be sent toward the nip part between the entrance rollers 24A and 24B.

FIG. 7 is a front view showing a modification of the guide mechanism 50 according to the first embodiment. In FIG. 7, the hollows 52 and 53 are provided on the side of the paper supply port 61 of the finisher 20 so that the axis 66 of the guide plate 62 is put in the hollow 52 and the axis 67 of the guide plate 63 is put in the hollow 53. The axis 64 of the guide plate 62 and the axis 65 of the guide plate 63 are supported on the inner side of the paper discharge port 51 of the MFP 10. The guide plates 62 and 63 can turn about the axes 64 and 65 as the fulcrum.

In the state where there is no step between the MFP 10 and the finisher 20, as shown in FIG. 7, the axis 66 of the guide plate 62 is located more closely to the carrying path for the sheet S than the rotation axis of the upper roller 24A is, and the axis 67 of the guide plate 63 is located more closely to the carrying path for the sheet S than the rotation axis of the lower roller 24B is. When the axes 66 and 67 of the guide plates 62 and 63 are put in the hollows 52 and 53, the guide plates 62 and 63 form a tapered shape narrowing from the discharge port 51 toward the paper supply port 61.

For example, when the floor surface where the finisher 20 is lower than the floor surface where the MFP 10 is installed, the state as shown in FIG. 8 can be seen. In the state of FIG. 8, the axis 66 of the guide plate 62 is located near the entrance of the hollow 52. The axis 67 of the guide plate 63 goes deep into the hollow 53. The guide plates 62 and 63 turn slightly downward (counterclockwise) about the axes 64 and 65 as the fulcrum. The sheet S carried by the paper discharge rollers 19 is guided by the upper guide plate 62 and is carried to the entrance rollers 24. Therefore, even when the height of the finisher 20 is lower, the sheet S is smoothly carried from the MFP 10 to the finisher 20.

Meanwhile, when the floor surface where the finisher 20 is installed is higher than the floor surface where the MFP 10 is installed, though not shown, the axis 66 of the guide plate 62 goes deep into the hollow 52 and the axis 67 of the guide plate 63 is located near the entrance of the hollow 53. Therefore, the guide plates 62 and 63 turn slightly upward (clockwise) about the axes 64 and 65 as the fulcrum. The sheet S carried by the paper discharge rollers 19 is guided by the lower guide plate 63 and is carried to the entrance rollers 24. Therefore, even when the height of the finisher 20 is higher, the sheet S is smoothly carried from the MFP 10 to the finisher 20.

As described above, in the first embodiment, even when a step is generated in the connecting part between the MFP 10 and the finisher 20, the sheet S is guided by the guide plates 62 and 63 and can be carried smoothly from the MFP 10 to the finisher 20.

Next, a second embodiment of the guide mechanism 50 will be described.

FIG. 9 is a front view showing the guide mechanism 50 of a sheet guide device according to the second embodiment, as enlarged. FIG. 9 shows the state where the MFP 10 and the finisher 20 are not connected with each other. FIG. 10 shows the state where the MFP 10 and the finisher 20 are connected with each other. FIG. 11 is a side view of the guide mechanism 50, as viewed from the side of the MFP 10 (the direction of arrow A in FIG. 9). FIG. 12 is a perspective view showing the guide mechanism 50, as exploded.

In FIG. 9, the MFP 10 has the paper discharge port 51 formed to the side of the finisher 20, and the finisher 20 has the paper supply port 61 formed to face the paper discharge port 51. In FIG. 10 and the subsequent drawings, the paper discharge port 51 and the paper supply port 61 are not shown. The paper discharge rollers 19 are located on the inner side of the paper discharge port 51. The sheet S passes between paper discharge guides 81 and 82. Slits 83 (see FIG. 12) which the upper roller 19A and the lower roller 19B of the paper discharge rollers 19 enter are formed in the paper discharge guides 81 and 82.

The paper discharge rollers 19 form a sheet carrying unit which carries sheets from the paper discharge port 51 of the MFP 10 to the paper supply port 61 of the finisher 20.

One end of a movable plate 84 that is flat and elastic is attached to the exit end of the paper discharge guide 81. A fixed member 85 is attached to the other end of the movable plate 84. The fixed member 85 has an H-shape and is hard. Regulating rollers 86A and 86B that are vertically arranged are attached to both ends of the fixing member 85. A guide tunnel 87 through which the sheet S can pass is fixed to the bottom side of the movable plate 84. A bottom plate 87A (FIG. 12) of the guide tunnel 87 is sloped toward the distal end of the movable plate 84.

Meanwhile, a pair of guide plates 91 and 92 is provided facing the paper supply port 61 of the finisher 20. An intermediate guide plate 93 is arranged between the guide plates 91 and 92. The sheet S passes between the guide plate 91 and the intermediate guide plate 93. The ends of the guide plates 91 and 92 on the side of the paper supply port 61 have sloped surfaces 91A and 92A which form a shape broadening toward the end. The end of the intermediate guide plate 93 on the side of the paper supply port 61 has a sloped surface 93A which forms a shape broadening toward the end at the same angle as the sloped surface 91A. Slits 94 which the upper roller 24A of the entrance rollers 24 enters are formed in the guide plates 91 and 93, and slits 94 which the lower roller 24B enters are formed in the guide plate 92 (see FIG. 12).

In the state where the MFP 10 and the finisher 20 are separate from each other, as shown in FIG. 9, the paper discharge guides 81 and 82 and the guide plates 93 and 92 face each other, and the movable plate 84 is located at a position higher than the carrying path (indicated by the chain-dotted line) for the sheet S. When the MFP 10 and the finisher 20 are aligned in height position and connected with each other, as shown in FIG. 10, the regulating roller 86A is located below the sloped surface 91A of the guide plate 91. The regulating roller 86B is located above the sloped surface 92A of the guide plate 92. The sheet S which is passed through the paper discharge rollers 19 passes through the guide tunnel 87 and is carried to the entrance rollers 24.

When the width of the guide plates 91 and 92 is L1, the width of the intermediate guide plate 93 is L2 and the width between the left and right regulating rollers (86A, 86B) is L3, L1>L3>L2 holds, as shown in FIG. 11. Therefore, the regulating rollers 86A and 86B are abutted against the sloped surface 91A or the sloped surface 92A but are not abutted against the sloped surface 93A.

FIG. 13 and FIG. 14 are explanatory views showing the operation of the guide mechanism 50 according to the second embodiment in the case where the MFP 10 and the finisher 20 are shifted from each other in height. For example, when the floor surface where the finisher 20 is installed is higher than the floor surface where the MFP 10 is installed, the state as shown in FIG. 13 can be seen.

In the state of FIG. 13, the lower regulating roller 86B is abutted against the sloped surface, 92A of the guide plate 92 and the movable plate 84 bends upward. The sheet S which is passed through the guide tunnel 87 passes over the sloped surface 92A of the guide plate 92 and is carried to the entrance rollers 24. Therefore, even when the height of the finisher 20 is higher, the sheet is smoothly carried from the MFP 10 to the finisher 20.

Meanwhile, when the floor surface where the finisher 20 is installed is lower than the floor surface where the MFP 10 is installed, the state as shown in FIG. 14 can be seen. In the state of FIG. 14, the upper regulating roller 86A is abutted against the sloped surface 91A of the guide plate 91 and the movable plate 84 bends downward. The sheet S which is passed through the guide tunnel 87 is carried to the entrance rollers 24 along the movable plate 84 and the sloped surface 93A of the guide plate 93.

Therefore, even when the height of the finisher 20 is lower, the sheet S is smoothly carried from the MFP 10 to the finisher 20. That is, the movable plate 84 serves as a guide which bends flexibly according to the step between the MFP 10 and the finisher 20.

As shown in FIG. 9, the paper discharge guide 82 and the lower roller 19B can turn in the direction of arrow B. Therefore, if jam occurs in the connecting part between the MFP 10 and the finisher 20, the paper discharge guide 82 and the lower roller 19B can turn in the direction B, thus enabling removal of the sheet without any obstruction by the regulating rollers 86A and 86B.

In the state where the MFP 10 and the finisher 20 are aligned with each other in height, as shown in FIG. 10, the diameter of the regulating rollers 86A and 86B and the width in the direction of height of the sheet carrying path (the distance between the guide plates 92 and 93) are substantially coincident with each other. Moreover, the vertical height position of the lower regulating roller 86B and the vertical position of the sheet carrying path are aligned with each other.

If the diameter of the regulating roller 86B is significantly larger than the width in the direction of height of the sheet carrying path, the regulating roller 86B is abutted against the guide plate 92 and the movable plate 84 bends largely even when the paper discharge port 51 and the paper supply port 61 are aligned with each other in height position. Thus, the sheet S ends up being guided obliquely upward. Meanwhile, if the diameter of the regulating roller 86B is smaller than the width in the direction of height of the sheet carrying path, the regulating roller 86B is not abutted against guide plate 92 and the movable plate 84 does not bend even when the paper discharge port 51 and the paper supply port 61 are shifted from each other in height position. Therefore, the sheet S cannot be guided.

Since the hard fixed member 85 is attached to the distal end of the movable plate 84, the pair of left and right regulating rollers 86A and 86B can contact the sloped surfaces 93A and 92A simultaneously without inclination.

FIG. 15 is a front view showing a modification of the guide mechanism 50 according to the second embodiment. In FIG. 15, the movable plate 84 is turned upside down and attached to the exit end of the paper discharge guide 82. The sloped surface 93A of the intermediate guide plate 93 in the finisher 20 is directed downward so that the sheet S can pass between the guide plates 91 and 93.

When the MFP 10 and the finisher 20 are connected with each other as the MFP 10 and the finisher 20 are aligned with each other in height position, as shown in FIG. 15, the regulating roller 86A is located below the sloped surface 91A of the guide plate 91. The regulating roller 86B is located above the sloped surface 92A of the guide plate 92.

For example, when the floor surface where the finisher 20 is installed is higher than the floor surface where the MFP 10 is installed, the state as shown in FIG. 16 can be seen.

In the state of FIG. 16, the lower regulating roller 86B is abutted against the sloped surface 92A of the guide plate 92 and the movable plate 84 bends upward. The sheet S which is passed through the guide tunnel 87 passes over the movable plate 84 and the sloped surface 93A of the intermediate guide plate 93 and is carried to the entrance rollers 24. Therefore, even when the height of the finisher 20 is higher, the sheet S is smoothly carried from the MFP 10 to the finisher 20.

Meanwhile, when the floor surface where the finisher 20 is installed is lower than the floor surface where the MFP 10 is installed, though not shown, the upper regulating roller 86A is abutted against the sloped surface 91A of the guide plate 91 and the movable plate 84 bends downward. The sheet S which is passed through the guide tunnel 87 is carried to the entrance rollers 24 along the movable plate 84 and the sloped surface 91A of the guide plate 91. Therefore, even when the height of the finisher 20 is lower, the sheet S is smoothly carried from the MFP 10 to the finisher 20.

In the state where the MFP 10 and the finisher 20 are aligned with each other in height position, as shown in FIG. 15, the diameter of the regulating rollers 86A and 86B and the width in the direction of height of the sheet carrying path (the distance between the guide plates 91 and 93) are substantially coincident with each other. Moreover, the vertical height position of the upper regulating roller 86A and the vertical position of the sheet carrying path are aligned with each other.

As described above, according to the second embodiment, even if there is a step on the installation surface when the MFP 10 and the finisher 20 are connected with each other, the guide mechanism 50 is provided and therefore the sheet S discharged from the MFP 10 can be supplied without causing the sheet S to collide with the finisher 20.

The invention is not limited to the above embodiments and various modifications can be made. For example, though an example of the finisher 20 having a stapler is described, the finisher 20 having a folding unit which folds a sheet bundle into two may also be employed. The finisher 20 having a puncher which punches holes in sheets may also be employed.

While certain embodiments have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the invention. Indeed, the novel apparatus and methods described herein may be embodied in a variety of other forms; furthermore, various omissions, substitutions and changes in the form of the apparatus and methods described herein may be made without departing from the spirit of the inventions. The accompanying claims and their equivalents are intended to cover such forms or modifications as would fall within the scope and spirit of the inventions. 

1. A sheet guide device comprising: a sheet carrying unit which carries a sheet from a paper discharge port of an image forming apparatus to a paper supply port of a finishing apparatus; and a pair of guide plates having one end attached to an inner side of the paper discharge port so as to be narrowed in a tapered form from the paper discharge port toward the paper supply port and having the other end attached to an inner side of the paper supply port, the pair of guide plates has one of the one end and the other end as a fulcrum and has the other as a turning end, and when the paper discharge port and the paper supply port are shifted from each other in height position, the turning end turns according to the quantity of shift in the height position.
 2. The apparatus of claim 1, wherein the paper discharge port and the paper supply port are formed parallel to a direction of width of the sheet, and a pair of upper and lower hollows is provided at both ends in a direction of width of one of the paper discharge port and the paper supply port, and the turning ends of the pair of guide plates are inserted in the hollows, and when the paper discharge port and the paper supply port are shifted from each other in the height position, the turning ends are turned in an up-and-down direction within the hollows.
 3. The apparatus of claim 2, wherein the hollows are sloped from entrance toward back.
 4. The apparatus of claim 2, further comprising: a pair of paper discharge rollers provided at a position facing the paper discharge port in the image forming apparatus; and a pair of entrance rollers provided facing the paper supply port in the finishing apparatus; wherein the hollows are provided at both ends in the direction of width of the paper discharge port, the turning ends of the pair of guide plates are inserted in the hollows, the fulcrums of the pair of guide plates are supported at a supporting part in the paper supply port, and each of the fulcrums is located more closely to a carrying path for the sheet than a center of rotation of the pair of entrance rollers.
 5. The apparatus of claim 2, wherein the pair of guide plates is energized by a spring so that the turning ends are directed toward the hollows.
 6. A sheet guide device comprising: a sheet carrying unit which carries a sheet from a paper discharge port of an image forming apparatus to a paper supply port of a finishing apparatus; a pair of guide plates provided in the finishing apparatus and having sloped surfaces with their one-side ends forming a shape broadening toward the paper supply port; an elastic movable plate which has one end attached inside the paper discharge port and other end protruding outside of the paper discharge port, and provided parallel to a carrying path for the sheet; and a pair of regulating rollers attached to both ends of the other end of the movable plate, wherein when the paper discharge port and the paper supply port are shifted from each other in height position, the regulating rollers contact the sloped surface of one of the pair of guide plates and bend the movable plate according to the quantity of shift in the height position.
 7. The apparatus of claim 6, wherein the other end of the movable plate is formed by a hard member.
 8. The apparatus of claim 6, further comprising: a pair of paper discharge rollers provided at a position facing the paper discharge port in the image forming apparatus; a pair of entrance rollers provided facing the paper supply port in the finishing apparatus; and a paper discharge guides provided above and below the carrying path for the sheet passing through the paper discharge rollers; wherein the one end of the movable plate is attached to a distal end of one of the paper discharge guides.
 9. The apparatus of claim 6, further comprising an intermediate guide plate having a narrower width than the pair of guide plates, between the pair of guide plates, wherein a sheet carrying path is formed between one of the pair of guide plates and the intermediate guide plate.
 10. The apparatus of claim 9, wherein the regulating rollers include a pair of upper and lower rotatable regulating rollers attached at both ends of the other end of the movable plate, and a diameter of each of the regulating rollers is made substantially the same as a width between one of the guide plates and the intermediate guide plate.
 11. A sheet guiding method comprising: carrying a sheet from a paper discharge port of an image forming apparatus to a paper supply port of a finishing apparatus; and providing a pair of guide plates having one end attached to an inner side of the paper discharge port so as to be narrowed in a tapered form from the paper discharge port toward the paper supply port and having the other end attached to an inner side of the paper supply port, the pair of guide plates has one of the one end and the other end as a fulcrum and has the other as a turning end, and when the paper discharge port and the paper supply port are shifted from each other in height position, the turning end turns according to the quantity of shift in the height position.
 12. The method of claim 11, wherein the paper discharge port and the paper supply port are formed parallel to a direction of width of the sheet, and a pair of upper and lower hollows is provided at both ends in a direction of width of one of the paper discharge port and the paper supply port, and the turning ends of the pair of guide plates are inserted in the hollows, and when the paper discharge port and the paper supply port are shifted from each other in the height position, the turning ends are turned in an up-and-down direction within the hollows.
 13. The method of claim 12, wherein the hollows are sloped from entrance toward back.
 14. The method of claim 12, wherein a pair of paper discharge rollers are provided at a position facing the paper discharge port in the image forming apparatus, and a pair of entrance rollers is provided facing the paper supply port in the finishing apparatus, the hollows are provided at both ends in the direction of width of the paper discharge port and the turning ends of the pair of guide plates are inserted in the hollows, and the fulcrums of the pair of guide plates are supported at a supporting part in the paper supply port and each of the fulcrums is located more closely to a carrying path for the sheet than a center of rotation of the pair of entrance rollers.
 15. The method of claim 12, wherein the pair of guide plates is energized by a spring so that the turning ends are directed toward the hollows.
 16. A sheet guiding method comprising: carrying a sheet from a paper discharge port of an image forming apparatus to a paper supply port of a finishing apparatus; providing, in the finishing apparatus, a pair of guide plates having sloped surfaces with their one-side ends forming a shape broadening toward the paper supply port; providing an elastic movable plate parallel to a carrying path for the sheet so that one end of the movable plate is attached inside the paper discharge port and the other end protrudes outside of the paper discharge port; and attaching a pair of regulating rollers to both ends of the other end of the movable plate, when the paper discharge port and the paper supply port are shifted from each other in height position, the regulating rollers contact the sloped surface of one of the pair of guide plates and bend the movable plate according to the quantity of shift in the height position.
 17. The method of claim 16, wherein the other end of the movable plate is formed by a hard member.
 18. The method of claim 16, further comprising: providing a pair of paper discharge rollers at a position facing the paper discharge port in the image forming apparatus; providing a pair of entrance rollers facing the paper supply port in the finishing apparatus; providing paper discharge guides above and below the carrying path for the sheet passing through the paper discharge rollers; attaching the one end of the movable plate to a distal end of one of the paper discharge guides.
 19. The method of claim 16, wherein an intermediate guide plate having a narrower width than the pair of guide plates is provided between the pair of guide plates, and a sheet carrying path is formed between one of the pair of guide plates and the intermediate guide plate.
 20. The method of claim 19, wherein the regulating rollers include a pair of upper and lower rotatable regulating rollers attached at both ends of the other end of the movable plate, and a diameter of each of the regulating rollers is made substantially the same as a width between one of the guide plates and the intermediate guide plate. 